Method for operating a combustion unit and a combustion unit

Abstract

A method for operating a combustion unit ( 1 ), a fuel ( 6 ) being burned with an oxygen-containing carrier gas ( 7 ) in at least one combustion space ( 2 ) with the release of an exhaust gas flow ( 8 ), ambient air ( 10 ) being separated into a product gas ( 12 ) which is enriched with oxygen and into exhaust air ( 13 ) enriched with nitrogen, a gas flow ( 9 ) being separated from the exhaust gas flow ( 8 ) and returned to the combustion space ( 2 ), the returned gas flow ( 9 ) being mixed with a gas flow ( 12 a ) of the product gas ( 12 ) to form a carrier gas ( 7 ). The carrier gas ( 7 ) and fuel ( 6 ) are supplied separately to the combustion space ( 2 ). The argon concentration in the returned gas flow ( 9 ) and/or in the carrier gas ( 7 ) is measured.

1 - 41 . (canceled) 
     
     
         42 . Method for operating a combustion unit, comprising the steps of:
 burning a fuel in at least one combustion space with an oxygen-containing carrier gas with the release of an exhaust gas flow,   separating ambient air into a product gas flow which is enriched with oxygen and into exhaust air flow enriched with nitrogen,   separating a gas flow from the exhaust gas flow and returning the separated gas flow to the combustion space, the returned separated gas flow being mixed with a the product gas flow to form a carrier gas,   separately supplying the carrier gas and fuel separately to the at least one combustion space,   measuring the concentration of argon in at least one of the returned gas flow and in the carrier gas, supplying a partial flow of the product gas directly to the carrier gas prior to entry into the combustion space or supplying another product gas flow directly to the combustion space for matching the composition of the carrier gas-fuel mixture in the combustion space to the brief change of the amount of fuel supplied to the combustion space,   wherein the mixing ratio of the returned gas flow and of the product gas flow and the volumetric flow of the carrier gas supplied to the combustion space and said other product gas flow which is supplied directly to the combustion space are controlled depending on the argon concentration measured such that for each load state of the combustion unit, an optimum mixture heat value of the product gas/carrier gas-fuel mixture in the combustion space is obtained.   
     
     
         43 . Method as claimed in  claim 42 , wherein the product gas flow is stored in at least one product gas accumulator and wherein said product gas flow and said other product gas flow are taken from said gas accumulator. 
     
     
         44 . Method as claimed in  claim 42 ,
 wherein the exhaust gas flow is separated into a first argon-enriched component flow and into a second argon-depleted component flow as the residual exhaust gas flow, and   using the first component flow to form the returned gas flow.   
     
     
         45 . Method as claimed in  claim 44 , wherein separation takes place in a separating tank which is cooled on one half side, the exhaust gas flow flowing into a cold zone region of the separating tank, the exhaust gas flow being cooled in the cold zone region, wherein an upward flow of at least one gas component out of the cold zone region into a warm zone region of the separating tank located above is effected by density differences between the gas components in the exhaust gas flow and wherein the first component flow in the warm zone region and the second component flow in the cold zone region are discharged from the separating tank. 
     
     
         46 . Method as claimed in  claim 42 , wherein said other product gas flow is stored in a secondary accumulator which is assigned to the combustion space. 
     
     
         47 . Method as claimed in  claim 44 , wherein separation takes place in a turbocharger, the exhaust gas flow being supplied to the turbocharger and being separated into two component flows by centrifugal force in a housing of the turbocharger and wherein the two component flows are discharged from the turbocharger separately from one another. 
     
     
         48 . Method as claimed in  claim 42 , wherein afterburning of the exhaust gas of the exhaust gas flow takes place in at least one combustion chamber connected downstream of the combustion space, the combustion chamber being supplied with product gas. 
     
     
         49 . Method as claimed in  claim 42 , wherein ambient air is automatically supplied to the combustion space when product gas generation is disrupted. 
     
     
         50 . Combustion unit, comprising:
 at least one combustion space for burning a fuel with an oxygen-containing enriched carrier gas and releasing of an exhaust gas flow,   at least one gas separation means for separating ambient air into an oxygen-enriched product gas flow and exhaust airflow enriched with nitrogen,   at least one mixing chamber, and   at least one gas return means, in the combustion space,   a gas return means for separating a return gas flow from the exhaust gas flow which is returned to the combustion space,   a mixing chamber for mixing the returned gas flow with the product gas flow to form the carrier gas,   means for supplying the carrier gas and fuel separately to the combustion space,   at least one measurement means for measuring the concentration of argon in at least one of the returned gas flow and the carrier gas,   wherein there is at least one product gas accumulator for product gas   and wherein at least one secondary accumulator for product gas is assigned to the at least one combustion space and is located in an immediate vicinity of the combustion space.   
     
     
         51 . Combustion unit as claimed in  claim 50 , further comprising an automatic control means for automatically controlling the ratio of the returned gas flow and the product gas flow in the carrier gas and for controlling the volumetric flow of carrier gas supplied to the combustion space depending on the measured argon concentration. 
     
     
         52 . Combustion unit as claimed in  claim 50 , wherein the secondary accumulator is fillable by the product gas accumulator. 
     
     
         53 . Combustion unit as claimed in  claim 50 , wherein the combustion space has at least one nozzle means for directly supplying product gas into the combustion space. 
     
     
         54 . Combustion unit as claimed in  claim 50 , wherein a combustion chamber for afterburning of the exhaust gas flow is located downstream of the combustion space. 
     
     
         55 . Combustion unit, comprising:
 at least one combustion space for burning a fuel with an oxygen-containing enriched carrier gas and releasing of an exhaust gas flow,   at least one gas separation means for separating ambient air into an oxygen-enriched product gas flow and exhaust airflow enriched with nitrogen,   at least one mixing chamber, and   at least one gas return means, in the combustion space,   a gas return means for separating a return gas flow from the exhaust gas flow which is returned to the combustion space,   a mixing chamber for mixing the returned gas flow with the product gas flow to form the carrier gas,   means for supplying the carrier gas and fuel separately to the combustion space, and   a turbocharger for separation of the exhaust gas flow into a first argon-enriched component flow and into a second argon-depleted component flow by centrifugal force.   
     
     
         56 . Combustion unit, comprising:
 at least one combustion space for burning a fuel with an oxygen-containing enriched carrier gas and releasing of an exhaust gas flow,   at least one gas separation means for separating ambient air into an oxygen-enriched product gas flow and exhaust airflow enriched with nitrogen,   at least one mixing chamber, and   at least one gas return means, in the combustion space,   a gas return means for separating a return gas flow from the exhaust gas flow which is returned to the combustion space,   a mixing chamber for mixing the returned gas flow with the product gas flow to form the carrier gas,   means for supplying the carrier gas and fuel separately to the combustion space,   wherein the at least one gas return means is a separating means with a separating tank which is cooled on one half side, the separating tank having a lower cold zone region and an upper warm zone region, wherein an entry opening of the separating tank discharges into the cold zone region, and wherein the cold zone region and the warm zone region each have at least one exit opening and being connected to one another via at least one gas-communicating linkage.   
     
     
         57 . Combustion unit as claimed in  claim 56 , wherein the separating tank has a plurality of baffles which are arranged in succession in the manner of a cascade in a through-flow direction of the separating tank, the baffles being arranged spaced apart from one another in the separating tank and the cold zone region being separated from the warm zone region by the baffles in sections transversely relative to the throughflow direction.